Feeding mechanism for sewing machines



my 4, 192s. 1,582,925

vH. F. GRUMAN vFIEEDING IECHANISH FOR SEWING IACHINES vFiled oct. 21,1924

um lll adorna,

Patented May 4, 1926.

UNITED STATES j 1,582,926 PATENT oFFicE.

HORACE F. GRUMAN, OF ST. LOUIS, MISSOURI, VASSIGINOB. TO LEWIS INVISIBLE STITCH MACHINE CO., 0F ST. LOUIS, MISSOURI, A CORPORATION OF MAINE.

FEEDING MECHANISM FOR SEWING MACHINES.

Application tiled October 21, `1924. Serial No. 744,917.

To all whom it may concern Be it known that I,.HoRAoE F. GRUMAN, citizen of the United States, residing at'St. Louis, and State of Missouri, have invented rcertain new and useful Improvements in Feeding Mechanism for Sewing Machines, of whichthe following is a specification.

This invention relates to new and useful improvements in feeding mechanisms for sewing machines generally, although more particularly to a top feeding mechanism.

It is a well known fact in this art that when feeding two superimposed fabrics through a sewing machine having a lower feed only, the lower pl being engaged by the usual 4-motion fee dogtends to feed faster than a. superimposed ly which engages the -presser foot. In ot er words the upper ply is not directly engaged by the lower feed dog and consequently it has a tendency to dra This dlsadvantage has been known an various top feed mechanisms have been constructed to overcome the objections stated.

. In the patent to Thomas J. Hayes, No. 1,474,966, issued November 20, 1923, there is provided .a top feeding mechanism which is in the nature of an attachment to the presser bar. This top feed is actuated from the nee# dle bar through the medium o-f an oscillatory lever having a sliding pivotal connection with a stud carriedby said needle bar. This construction necessitates the formation of a fork at the front end of said actuating lever and this form is of such a length as to project in front of the needle bar and interfere with the hands o-f the operator and therefore constitutes a forwardly extending projection whichreciprocates at a high rate of speed and is therefore dangerous to the operator.

The 'rincipal object of my invent-ion is to provide an improved construction over the Hayes patent above noted whereby the projection above described is eliminated and consequently all danger to the operator is avoided.

With the above and other objects in view which will more readily appear as the nature of the invention is better understood, the same consists in the novel construction, combination and arrangement of parts hereinafter more fully described, illustrated and claimed.

In the accompanying drawings which show one form of my invention:

Figure 1 is a side elevation of a top feed mechanism constructed in accordance with my invention, l

Figure 2 's a side elevation from the opposite direction,

Figure 3 is a view somewhat similar to Figure 2 but certain of the parts being removed to better disclose the construction.

Figure 4 is a horizontalsectional view taken on the line 4--4 of Figure 1, and

Figure 5 is a detail sectional view taken on the line 5-5 of Figure 2.

Referring to the accompanying drawings, 5 designates the usual sewing machine head which carries a vertically reclprocatory needle bar 6 and a vertically disposed presser bar 7 which is arranged 1n rear of said needle bar. The needle bar 6 supports a needle 8 through the medium of a needle clamp 9,

.the needle shank being clamped between the needle bar and the clamp by means of a clamping screw 10,- which has threaded engagement through a stud 11 which projects laterally from the needle clamp 9 and is integral therewith. ,The screw 10 is-provided with ahead 12 having a diameter somewhat less than the diameter of the stud 11. Associated with the needle 8 isv a throat plate 13 'and the usual 4-motion lower feed dog 14,.

The entire upper feed mechanism is carried in a presser foot frame 15 which includesv a detachable presser foot 16. This frame is detachably supported on the lower end of the presser bar 7 4by means of a set screw 17. The frame 15 extends in rear of the presser bar 7 and carried'by the upper rear end of said 'frame is a boss 18 in which is mounted a headed bearing stud 19 having its longitudinal axis disposed in a horizontal plane and in a plane at right angles to the direc-tion of feed, the stud being held against movement relative to the frame by means of a set screw 20. Journaled on the stud 19 between the head thereof and the boss 18 is a cam 21 which is oscillated by the needle bar to impart proper movements to a top feed dog 22.

The top feed dog 22 works through an opening 23 in the resser foot 16 and is pivoted at its rear end as at 24 to the lower end intermediate its ends as at 26vto the frame presser bar 7 and the cam 2l. The top feed dog 22 is' positively moved rearwardly to 'A feed the material by reason of the lever 25 s being oscillated through the medium of the cam surface 27 of the cam 21 engaging the upper end of the lever. The top feed dog 22 is automatically returned to its initial position, that is, moved forwardly, by means of a spring 28 which functions `as stated upon withdrawal of the cam surface 27 from the lever 25.

The top feeddcg 22 is also given up and down movements, the down movement being positively imparted through the medium of al depresser lever 29 and the 'up movement being automatically imparted by the spring 28. The lever 29 is fulcrumed on the pivot 26- and the lower end thereof engages a shoulder 30 fixed to the. top feed dog. The

. upper end of the lever is formed with a v:se

lthe length of feed travel of the top clearance slot 3l which encompasses the hub 32 of the cam 21. The cam 2l carries a Vlaterally extending roller' bearing stud 33 which cooperates 'with the cam-shaped upper portion 34 of the depresser lever 29.- As the roller'of the stud 33 rides up the appropriate cam surface of said lever 29, it rocks the `upper end of the lever forwardly to a detinite extent, causing the lower end of the lever to press down the top feed dog against lthe tension of the spring 28 and then as the roller rides along the surface 35 of said lever, it holds the latter down.V

ln order to oscillate the cam 21, I have provided a connection with the'needle bar 6. This connection includes a telescopic actuating lever consisting of a rod 36 and a socket arm 37, the socket -arm being integrally connected at its rear'end to a laterally otiset tail piece 38 which is journaled on the headed stud 19 and lies flat against the right in the tail pieceBS and has threaded 'engagement with vthe cani 21. Thus the actuating lever is positively connected to the cam 2l throuvh an adjustable connection which permits the cam to be readily adjusted to vaar ree dog. The front end' of the'rod 38 1s provided with a socket Lil which has pivotal clamp; that the socket arm of the telescopic l actuating lever is offset from the tail piece whereby the cooperating :69d will have freedom of movement and whereby a construction is provided which will permit of the bore being readilydrilled and reamed, and that by means of the adjustable connection between the tail piece ofthe actuating leverv and the cam the feed travel of the top feed.l

dog may be readily adjusted.

TWithout further description'it is thought vl that the many features and adavantages of the invention will be readily apparent and it will, of course, be understood that changes in the form, proportion .and minor details 'of construction maybe resorted to without departing from the spirit of the invention or scope of the appended claim.

I claim:

In a sewing machine top feeding mechanism, the combination of apresser-bar, a vertically reciprocatory needle bar located in front of said presser bar, a needle clamp carried by .said needle bar and having 'a .laterally extending stud, a top feed dog, a frame carried by said presser-bar and locatedin rear of said needle bar, a cam journalled on said frame, means operated by said cam for imparting feeding movements to said feed dog, and means for oscillating j said cam consistingI of a telescopic actuati ing lever having its 'longitudinal aXis disposed parallel to the line of -feed and com-- prising a rod and a socket arm, the rod having its outer end tixedly-journalled on the? stud of the 4needle clamp and the socket armbeing positively connected to said cam.

In testimony whereof I hereunto-ax my signature. I

HORACE F. GRUMAN, 

